ORIGIN OF OUR HANDS AND BACKBONE 549 



lung fish, which is a living example of an ancient family, 

 a blue-blooded aristocrat ! 



If you will examine one of these strange creatures, 

 you will find that it has four fins, corresponding to the 

 four limbs of a man and beast. 



The front fins of any ordinary fish correspond, bone 

 for bone, with those of your own arm; but the bones 

 are shortened and broadened, and the hand is composed 

 of many fingers called rays. 



Study this out for yourselves, at the museums or in 



Comparative Diagram of Horse and Bird 



your illustrated natural history books, for we must 

 hurry along in this chapter to the less complicated and 

 more simple anatomy of land animals. 



The fish is not remarkable for its brains, and its 

 hands are very crude affairs, only suitable for paddles, 

 for balancing paddles; the real propelling power of the 

 fish is its tail. But a little further in the line of evolu- 

 tion we will find that the alligator's fins or hands are very 

 much like our own. It is the same with the frog, the 

 newts, and salamanders, shown in the previous chapters, 

 and also with those extinct monsters of gigantic propor- 

 tions whose bones you will find exhibited at the Museum 

 of Natural History in Central Park. In the chapter on 



